The primary goal of the Quality Assurance Review Center is to maintain a responsive, supportive Quality Assurance Program in Radiotherapy for Cooperative Groups. We wish to continue development and implementation of the Program, since it has proven effective in improving the performance of the many gains accomplished in the past decade, leading to improvements in Group performance and with an elevation in sophistication of the Radio-therapy and Physics community in supporting clinical trials, our program, in the future, should take advantage of the improvements without losing ground in the process. In this grant cycle, we propose to undertake a modernization of our Data Management system. We will improve methods of data transfer to Group Investigators and Statistical Offices, with a wide rang of formats. We further propose to reorient Physics support for Group trials by modifying their participation in the development of protocols, in the way Physics data is accumulated and develop a novel approach to the study of radiation effects. The QARC has acted as a research resource for the Cooperative Groups; we are proposing to establish this as a recognized function at QARC. This includes developing normal tissue protocol questions. Secondly, because of the robust data-base that we have developed, we can work with Group Investigators and Statistical Offices to make available subsets of our data for correlative analyses of the radiotherapy performance as it relates to outcome. Because of QARC's recognized ability for Data Management, we have accepted responsibility for accumulation of Diagnostic Imaging data not necessarily a component of the section on Data Management for Diagnostic Imaging materials to support Group trials. Since its initiation a decade ago, QARC has responded to a demonstrated need of the Radiotherapy community in Cooperative Group trials and we propose to continue to be responsive to the changing needs during the period of this grant proposal.